| 摘要 |
<p>1355924 Treatment of chloride TiO 2 E I DU FONT DE NEMOURS & CO 30 June 1972 [30 June 1971] 30709/72 Heading C1N TiO 2 from the vapour phase oxidation of TiCl 4 is calcined at 500-1050‹ C. in the presence of 0À05-1% by wt. of alkali metal and 0À05- 3% by wt. of phosphorus (calculated as P 2 O 5 ), and then dry milled with at least 0À05% by wt. of an amine dispersing agent. The TiCl 4 may be co-oxidized with SiCl 4 or AlCl 3 to give anatase or rutile resp. It may be neutralized with NH 4 OH before calcination. The alkali metal may be added as a sulphate, chloride, hydroxide, carbonate, sulphite, or phosphate, e.g. KOH, NaOH, or LiOH. The phosphorus may be present from co-oxidation of PCl 3 or may be added as alkali metal phaosphate or ortho, meta, or pyro-phosphoric acid. The dispersing agents exemplified are monoethanolamine, biethanolamine, and 2-amino-2-methyl-1-propanol, others are mentioned (the term includes quaternary compounds and chelates). Milling may be effected in a fluid energy mill with steam, or in a ring roll mill.</p> |
